MEMORANDUM OPINION AND ORDER
CARLTON W. REEVES, District Judge.
Before the Court are the United States' motion to dismiss, Docket No. 3, and the plaintiff's motion to strike the United States' rebuttal on the motion to dismiss, Docket No. 9. Both motions have been fully briefed and are ripe for review. The motions are DENIED.
I. Factual and Procedural History
The parties dispute whether the plaintiff, Jimmy McBeath, has satisfied the jurisdictional requirements of the Federal Tort Claims Act ("FTCA"), such that he may move forward with the claims presented to this Court. McBeath's complaint alleges that he suffered multiple personal injuries because of the negligent or reckless driving of an Army National Guardsman who caused an auto accident on October 26, 2005, while operating a Guard vehicle. Nearly two years later, McBeath initiated an administrative claim against the United States by sending a Standard Form 95 to the Department of Defense ("DOD"), via overnight delivery service, on October 24, 2007. McBeath asserts that he never received any response regarding his attempt to invoke the administrative process. And he now argues that, because his claim "was never accepted nor rejected, " he is entitled to seek damages under 28 U.S.C. § 2675(a).
The defendant has moved to dismiss this lawsuit pursuant to Federal Rule of Civil Procedure 12(b)(1). Although the defendant acknowledges that McBeath's administrative claim was received by DOD,  it contends that McBeath failed to timely present an administrative claim form to the appropriate agency, as required by the FTCA. The basis for this contention is two-fold: First, the defendant claims that DOD was not the appropriate agency for the purposes of McBeath's claim, which arises from conduct by the Army National Guard. Second, the defendant claims that McBeath's administrative claim was never presented to DOD because the parcel containing McBeath's Standard Form 95 was deemed undeliverable under Pentagon protocol and returned to McBeath's counsel on November 9, 2007.
McBeath has moved to strike the defendant's rebuttal in its entirety. He argues that the rebuttal reflects an inappropriate change in position that is inconsistent with the assertions of the defendant's opening brief, where it denied having ever received McBeath's administrative claim. The defendant opposes the motion, contending that its rebuttal merely responds to information that McBeath presented for the first time in his response to the motion to dismiss.
Both motions are denied for reasons provided below.
II. Legal Standard
Federal Rule of Civil Procedure 12(b)(1) allows a party to challenge the trial court's subject-matter jurisdiction to hear a case. Ramming v. United States, 281 F.3d 158, 161 (5th Cir. 2001). A challenge of this type concerns "the most fundamental requirement of a court's [constitutional] authority" to adjudicate a case; the subject-matter jurisdiction requirement cannot be waived. Chickaway v. United States, 823 F.Supp.2d 452, 454 (S.D.Miss. 2011) (quoting Steel Co. v. Citizens for a Better Env't, 523 U.S. 83, 89 (1998)).
The party asserting jurisdiction "constantly bears the burden of proof that jurisdiction does in fact exist." Id. (citations omitted). When a defendant's Rule 12(b)(1) motion makes a "factual attack" by submitting "affidavits, testimony, or other evidentiary materials, " the plaintiff must also "submit facts through some evidentiary method and has the burden of proving by a preponderance of the evidence that the trial court does have subject matter jurisdiction." Paterson v. Weinberger, 644 F.2d 521, 523 (5th Cir. 1981). The motion should be granted "only if it appears certain that the plaintiff cannot prove any set of facts in support of his claim that would entitle [him] to relief." Ramming, 281 F.3d at 161 (citation omitted).
III. Law and Analysis
McBeath's claim is subject to the procedural requirements of the FTCA, which bars claims for money damages against the United States "unless the claimant shall have first presented the claim to the appropriate Federal agency and his claim shall have been finally denied by the agency in writing." 28 U.S.C. § 2675(a). This requirement "is no mere procedural nicety, " rather it stands as "a jurisdictional prerequisite to filing suit." Chickaway, 823 F.Supp.2d at 455 (citations omitted); see also In re FEMA Trailer Formaldehyde Products Liability Litigation, 646 F.3d 185, 189 (5th Cir. 2011). But cf. Scogin v. United States, No. L-12-20, 2013 WL 391164, *2 n.3 (S.D. Tex. Jan. 30, 2013) (questioning whether the Fifth Circuit cases that find the FTCA limitations period to be jurisdictional, rely on abrogated precedent). If the agency has not finally ruled on a properly filed claim after six months, however, "the claimant may treat the agency's failure to act as a final denial and he may file his suit at any time thereafter." McCallister v. U.S. ex rel. U.S. Dep't of Agric., 925 F.2d 841, 843-44 (5th Cir. 1991).
Both the FTCA and the Code of Federal Regulations offer guidance for identifying a properly presented claim under section 2675(a). The FTCA provides that administrative claims must be "presented in writing to the appropriate Federal agency within two years after such claim accrues or unless action is begun within six months after the date of mailing, by certified or registered mail, of notice of final denial of the claim by the agency to which it was presented." 28 U.S.C. § 2401(b). The statute defines the term "Federal agency" rather broadly, to include "the executive departments, the judicial and legislative branches, the military departments, independent establishments of the United States, and corporations primarily acting as instrumentalities or agencies of the United States." 28 U.S.C. § 2671. Federal regulations offer further instruction, providing that the appropriate agency is the one "whose activities gave rise to the claim." 28 C.F.R. § 14.2. Failure to meet any of these conditions would bar a lawsuit for failure to satisfy the FTCA's jurisdictional requirements. In re FEMA Trailer Litig., 646 F.3d at 189.
Here, McBeath admits that the FTCA required him to file an administrative claim. He contends that he satisfied this requirement by submitting his claim to DOD, and that this litigation should therefore proceed. In support, he has provided copies of his administrative claims form (a Standard Form 95 Claim for Damage, Injury, or Death) and of the UPS tracking summary showing that the form was delivered to DOD on October ...